Reducing saturation lowers the range of motion needed to reach full lock.
Increasing it obviously increases the amount of movement needed.

Linearity is used to smooth out, or exaggerate inputs. Decreasing linearity will smooth out input spikes, reducing too much and your wheel will feel like its lagging, as you need larger and larger inputs to get a response.
Increasing the value will make your wheel feel more responsive but too high and it can start to feel twitchy.

I think the settings you may have in your profiler in windows (degrees of turn etc) and personal preferences will affect what saturation/linearity feels right for you. So there is no real hard and fast rule, what feels great to one person, may feel laggy or too urgent to someone else.

thats for the info paul. I think I will turnn the saturation down to 90. not to sure about the linerity thou, think i will just have to fiddle around with it. would like to see wat other people use and maybe try there setup too.

I have to say i am loving useing the wheel with traction and abs OFF and manual gears.Its great fun but my times are still slower than when i have then turned on. just have to keep practicing.

When you guys racin online in sprint mode do ye turn abs and traction OFF. i find it very hard online.